The `goto` Statement

Part of the Logic & Flow section of Coddy's GO journey — lesson 4 of 68.

The goto statement in Go allows you to transfer control directly to a labeled statement within the same function. While Go includes this feature, it's rarely used in modern Go programming because clearer control structures like loops and if statements are preferred.

To use goto, you first define a label by writing an identifier followed by a colon. Then you can jump to that label using goto followed by the label name.

func main() {
    i := 0
start:
    fmt.Println("Count:", i)
    i++
    if i < 3 {
        goto start
    }
    fmt.Println("Done!")
}

In this example, the program jumps back to the start label until the condition is no longer met. However, this same logic would be much clearer using a for loop. The goto statement can make code harder to read and maintain, which is why it's generally discouraged in favor of structured control flow.

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

Challenge

Easy

In this challenge, you'll practice using the goto statement to create a simple retry mechanism. You're building a connection system that attempts to establish a connection and retries a specific number of times if it fails.

You will receive two inputs:

A string representing the maximum number of retry attempts (e.g., "3")
A string representing the attempt number that will succeed (e.g., "2")

Your task is to:

Parse the maximum retry attempts from the first input
Parse the success attempt number from the second input
Use a goto statement with a label to implement the retry logic
Start with attempt number 1 and increment after each failed attempt
For each attempt that fails, print "Attempt [attempt_number] failed"
When the attempt number matches the success attempt number, print "Attempt [attempt_number] succeeded" and exit
If you exceed the maximum retry attempts without success, print "All attempts failed" and exit

Use the goto statement to jump back to the retry label when an attempt fails and you haven't exceeded the maximum attempts. The attempt numbers should start from 1.

Cheat sheet

The goto statement transfers control directly to a labeled statement within the same function. Define a label with an identifier followed by a colon, then jump to it using goto:

func main() {
    i := 0
start:
    fmt.Println("Count:", i)
    i++
    if i < 3 {
        goto start
    }
    fmt.Println("Done!")
}

While goto is available in Go, it's rarely used in modern Go programming as structured control flow like loops and if statements are clearer and more maintainable.

Try it yourself

package main

import (
    "fmt"
    "strconv"
)

func main() {
    // Read input
    var maxRetriesStr string
    var successAttemptStr string
    fmt.Scanln(&maxRetriesStr)
    fmt.Scanln(&successAttemptStr)
    
    // Parse inputs to integers
    maxRetries, _ := strconv.Atoi(maxRetriesStr)
    successAttempt, _ := strconv.Atoi(successAttemptStr)
    
    // Initialize attempt counter
    attempt := 1
    
    // TODO: Write your code below
    // Use goto statement with a label to implement retry logic
    
}

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.